The present invention relates to the art of gamma
It finds particular application in conjunction with dual head, rotatable gamma cameras and will be described with particular reference thereto. It is to be appreciated, however, that the invention will also find application in conjunction with single detector head gamma cameras and other medical diagnostic equipment.
Heretofore, gamma cameras have included a relatively large, detector head. In some gamma cameras the head was mounted on an arm or pair of arms to facilitate positioning and moving the head. The arm(s) were mounted for rotating the head about a first axis to enable the head to move along a path encircling the patient. The head was typically mounted pivotally to the pair of arms along an axis transverse to the first axis.
In many models, the arms were centrally pivoted to carry a counterweight for balancing the camera head. Due to the significant volume of lead in the detector head and associated collimators, the counterweights were of significant size. For dual head cameras, a second pair of arms, a second detector head, and a second set of counterweights were provided.
In another prior art camera, the head was mounted on a longitudinally extending beam to traverse back and forth therealong. The beam was mounted at opposite ends to be rotated around the patient while remaining parallel thereto.
In another prior art gamma camera, a pair of stationary circular guide tracks were provided surrounding the patient. The camera head was mounted to the guide tracks to rotate about the longitudinal axis of the patient. Pivotal interconnections were provided such that the head could be rotated about an axis parallel to the longitudinal axis. However, the camera head could not be rotated about axes transverse to the longitudinal axis, limiting its freedom of positioning.
In a prior art three head system, three heads were mounted to a rotatable disk. The heads could move toward and away from the central axis along three, 120.degree. displaced axes, all transverse to the longitudinal axis. However, the heads were not amenable to rotation to face other than parallel to the longitudinal axis.
The present invention contemplates a new and improved gantry assembly that provides more freedom of head positioning.